Economists polled by Reuters had forecast claims slipping to 300,000 last week. A Labor Department analyst said there were no special factors influencing the state level data.

The four-week average of claims, considered a better measure of labor market trends as it irons out week-to-week volatility, rose 4,750 to 300,750. But at that level, it remains consistent with solid job growth and claims are back at their pre-recession levels.

U.S. Treasury debt prices were little changed on the data, while the U.S. dollar slipped slightly against other major currencies.

The claims report covered the period during which the government surveyed employers for August's nonfarm payrolls data. The four-week average of claims fell 8,500 between the July and August survey periods, suggesting another month of relatively strong job gains.

Nonfarm payrolls increased by 209,000 in July, marking the sixth consecutive month that job growth topped 200,000, a sign of strength last seen in 1997. The firming jobs picture appears to have caught policymakers by surprise.

Minutes of the Federal Reserve's July 29–30 policy meeting published on Wednesday showed officials viewing the improvement in labor market conditions as "greater than anticipated" and hinted that could lead to an early interest rate increase.

The U.S. central bank had previously described the labor market slack as "significant", but the minutes showed many policymakers thought this characterization "might have to change before long."

The Fed has held its benchmark interest rate near zero since December 2008.